1. Field of the Invention
The present invention relates generally to ladders and in particular to ladder stabilizers which are attached to a ladder and provide safety by reducing the possibility of slipping or tipping.
2. Description of Related Art
Ladders are known to be unstable and often require the assistance of a second person for steadying the ladder when a first person has climbed the ladder. However, another person is not always available when a ladder has to be used. There have been many devices made for stabilizing a ladder, and yet they do not solve the problems of being adjustable to all site conditions, convenient to use, easily installed on the ladder, compromising the integrity of the ladder, interfering with the use of the ladder, retractable and out of the way for storage, and providing stabilization when one side of the ladder is close to a wall.
U.S. Pat. No. 3,891,054 issued to Clayton E. Larson in 1975 discloses a step ladder stabilized by channel members which are fixed on each side of the lowest rung of the ladder and have an extendable member. Braces are provided at the upper rungs to provide rigidity and resistance against sway. However, it is not adjustable to all site conditions and adds very little stabilization to the ladder.
U.S. Pat. No. 4,964,488 issued to John V. Stewart on Oct. 23, 1990 discloses a step ladder stabilizer for a step ladder comprising a brace hinged to a ladder rail and an arm hinged to the rail at a lower position trussing the brace. The stabilizers on each side of the ladder fold against the front of the ladder. However, this ladder stabilizer is not adjustable to all site conditions and it interferes with the use of the ladder when not in use.
U.S. Pat. No. 5,868,222, issued to Francois Charbonneau on Feb. 9, 1999 discloses an extension ladder having a telescopic tube mounted to each side of the ladder's lower section and a lateral brace to support the telescopic tube extending away from each side of the ladder. However, the telescopic tubes bolt to the ladder which may compromise the integrity of the ladder, it is not easily installed on the ladder, and it is cumbersome and inconvenient to use. Also, it has removable pins and clips which are easily lost.
U.S. Pat. No. 4,147,231, issued to Douglas A. Chantler et al. on Apr. 3, 1979 discloses a ladder stabilizing device connected on the outer sides of the side pieces of the ladder. The device comprises outwardly extensible legs having an upper leg part connected to a slide plate on the side of the ladder which adjusts up and down. A lower leg support extends from the side of the ladder near the bottom and extends out to the upper leg part at its lower end. The upper and lower leg parts lie flat against the side of the ladder for storage when the ladder is not in use. However, this device lifts the ladder legs off the surface which eliminates the stability which otherwise would be provided by these legs. Also, this device is cumbersome and inconvenient to use.
U.S. Pat. No. 4,519,477, issued to Robert Ralston on May 28, 1984 discloses an adjustable stabilizer device for an extension ladder with hollow rungs comprising two stabilizing elements, an upper bracket and a lower bracket. Each stabilizing element connects to an upper right angle bracket which connects to a side wall bracket. The stabilizing elements are connected to each other by rods which extend through the hollow rungs of the ladder and attach to the side wall brackets. When the ladder is not in use the stabilizer elements are retained flush against the sides of the ladder for storage. However, this device is not adjustable to all site condition, is cumbersome and inconvenient to use, and has removable pins and clips which can be easily lost.